The first edition to A Guide to Bone Marrow Transplantation was published 10 years ago. At that time we perceived a need for an introductory text to the area of marrow transplantation, a rapidly developing field with few general texts avail­ able. Since then the situation has changed dramatically. Several introductory texts, therapeutic manuals and comprehensive volumes have been published. There is a heightened awareness of the availability, utility and potential of bone marrow transplantation, and of peripheral blood stem cell transplantation in particular. In many cases stem cell transplantation is being practiced by physi­ cians as a standard therapy. For those reasons we weighed carefully the question whether the Guide was still useful or even had a place. The feedback we received from physicians in practice or in training (including both hematologists and other physicians), as well as from nurses, physicians assistants, nurse practitioners, and other personnel in­ volved in one way or another in hematopoietic stem cell transplantation indicat­ ed that such a text was still desirable as an introduction that focused on princi­ ples rather than the latest up-to-date results.